Method and apparatus for cutting left-handed threads



E. IBACH.

METHOD AND APPARATUS FOR CUTTING LEFT HANDED THREADS.

APPLICATION FILED JAN-24,1919.

Patented; Apr. 27, 119290 2 SHEETS-SHEET l.

l1 1TH IN VEN TOIT. [/ifi/ mam E. JBACH. METHOD AND APPARATUS FOR CUTTING LEFT HANDED THREADS.

APPLICATI ON FILED JAN. 24,1919- Patented Apr. 27 192D,

2 SHEETS-SHEET 2- INVENTOR. 607 Maw? "4 2 mm .t-(l

ATTORNEY our @JFFJIQE.

IBAGH OFPHILADELPHIA, PENNSYLVANIA, ASSIGNOR T0 BUDD WHEEL CORPORATION, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF VIRGINIA.

Specification of Letters Patent.

Patented Apr. 27, 192(1).

Application filed January 24:, 1919. Serial No. 272,892.

I '0 all whom it may concern:

Be it known that I, EMIL IBAoH, a citizen of Germany, residing at Philadelphia, county of Philadelphia, and State of Pennsylvania, have invented certain new and useful Improvements in Methods and Apparatus for Cutting Left-Handed Threads, of which I declare the following to be a full, clear, and exact description.

My invention relates to an improved method and apparatus for cutting lefthanded threads, and more particularly for cutting left-handed threads upon wheel hubs, especially wheel hubs of the character designed for use with wire wheels.

One of the objects of my invention is to provide a method for cutting left-handed' threads in which it will be unnecessary to reverse the direction of movement of the head-chuck of the lathe from its ordinary clockwise direction of rotation.

A further object of my invention is to provide an improved method and apparatus for cutting left-handed threads, wherein the work is inserted in the die-head and drawn outwardly without the necessity of revers ing the direction of movement of the headchuck.

Another object of my invention is to provide an improved chaser for use in a lathe operating in accordance with my improved method.

Further objects of this invention relate to economies of manufacture and details of construction as will hereinafter appear from the detailed description to follow.

I accomplish the objects of my invention in one instance by the devices and means described in the following specification, but it is evident that the same may be varied widely without departing from the scope of the invention, as pointed out in the appended claims.

A structure illustrating one embodiment of my invention and themethod of operating the same, which may be the preferred, is illustrated in the accompanying drawing, forming a part hereof, in which:

Figure I is a side elevation of a portion of a lathe, showing the work held in proper operative position in the jaws of'the headchuck.

Fig. II is a fragmentary enlarged view partially in section of the die-head showing the usual manner.

the position of the work thereln at the beginning of the cutting operation.

Fig. III is an enlarged detailed view, partially in section, showing the work at the end of the cutting operation, and its position relative to the die-head.

Fig. IV is an enlarged perspective view of one of the chasers used in my improved method.

In the drawing, similar reference characters refer to corresponding parts throughout the several views.

Referring to the drawing, 10 indicates the bed frame of an ordinary lathe, provided with the usual head-stock 11 and tool-turret 12. The head-stock 11 carries the usual head-chuck 13 provided with clamping jaws 14: for firmly securing the work 15 in proper position relative thereto. The usual toolturret 12 is provided with a spindle l6 carrying a die-head '17 in which the cutting thread chasers 18 are releasably mounted in It will be noted, upon reference to Figs. III and IV, that the cutting portion 19 of the chaser 18 is located upon the outer section 20 of the chaser. In other words, the cutting section of the chaser is located, when the chaser is in position toward the outer face of the die-head. The centering portion 21 of the chaser is located adjacent the inner side of the chaser, or toward the interior of the die head when the chaser is secured in operative position therein.

In the usual method of cutting left-handed threads, the work is secured to the headchuck and the head-chuck is rotated in a counterclockwise direction, or from the operator, while the die-head is fed longitudinally of the machine and over the work carried by the head-chuck, for cutting threads upon the exterior surface of the work. In this method of cutting the threads, the centering portions of the chaser should be placed toward the exterior face of the diehead, for the purpose of centering the work with respect to the die-head, as the same passes thereover for the'purpose of cutting the threads.

In accordance with my improved method for cutting left-handed threads, it is unnecessary to reverse the usual direction of movement of the head-chuck, the same being constantly turned in the usual clockwise In operating upon the work in this direction, I form the centering portion 21 upon that side of the chaser which is positioned toward the inner part of the die-head, while the cutting portions are formed upon that side of each of the chasers which is toward the outer face of the die-head when the chasers are secured in position therein.

It will be seen, therefore, from the foregoing description, that I have devised a simple and eflicient method of cuttinglefthanded threads upon the outer surface of work of this character, wherein it is unnecessary to change the direction of .rotation of the head-chuck witlr each operation, but the head-chuck may be continuously'rotated in the usual clockwise direction toward the operator at all times. This method results a considerable saving of time and labor in the cutting of left-handed threads, and renders that operation as simple as the usual method of cutting right handed threads.

i While I have described my invention in more or less detail, and as being embodied incertain precise forms, I donot desire or intend to be limited thereto, but on the contrary my invention contemplates broadly all changes, as well as the omission of immaterial elements and the substitution of equivalents therefor, as circumstances may suggest or conditions render expedient.

Having thus described my invention, what I. claim as new and desire to secure by Letters Patent,- is r 1. A method-of cutting left-handed threads threads comprising mounting the work in a chuck member of a lathe, mounting a thread chaser on a tool holding member of said' lathe, rotating one of said members in a clockwise direction, and simultaneously feeding the other member away from said member.

3. A method of cutting left-handed threads comprising mounting the work in a chuck member of a lathe, mounting a plurality of thread chasers on a-tool-holding member of said lathe, rotating said chuck member in a clockwise direction, and simultaneously feeding the tool-holding member away from said chuck member.

4. In an apparatus for cutting left-handed threads, the combination of a die-head, a plurality of thread chasers removably mounted .in said die-head and extending radially thereof, each of said chasers having abeveled centering surface on the inside edge of its operating face, work holding means rotatable in a clockwise direction, and means for feeding said die-head away from said work holding means.

5. In an apparatus for cutting left-handed threads, the combination of a die-head having a central recess adapted to receive the work, and a plurality of thread chasers removably mounted in and extending radially of said die-head, each of said chasers having a beveled centering surface, on the inside edge of its operating face and a cutting portion on the outside-edge thereof.

In testimony whereof I afiix my si ture.

EMIL IB G 

